Modular valve assembly

ABSTRACT

A pre-assembled valve mechanism for use in valve controlled internal combustion engines and the like which is constructed and arranged to be installed and removed quickly as a unitary module with minimum effort and expenditure of time; the module comprising a cylindrical housing with valve seat and exhaust port, a headed valve cooperable with the seat, a valve guide, a return spring and a valve actuating cam follower coaxially mounted in operating position with the housing.

This invention relates generally to valve mechanisms useful with eitherintake or exhaust ports of internal combustion engines, pumps and thelike and more particularly is directed to a novel self-contained unitaryvalve module.

In the typically familiar internal combustion engine, by way of generalexample, intake and exhaust valves for controlling combustion andexhaust cycles of the engine are mounted over intake and exhaust portsto control the inflow of combustible fuel mixtures and the outflow ofexhaust gases. Frequently, such ports usually have annular permanent orinsert valve seats engageable with the head of an associated mushroomtype valve having an elongated valve stem and return spring coupledbetween the valve stem and a fixed support for holding the valve headclosed against its seat. A rotatably driven cam commonly engages thelower end of the valve stem or an intervening lift rod periodically tocompress the return spring and lift the valve head off its seat.

In the event of valve failure, such as a warped or broken valve head orstem, scored valve seat, defective return spring or like fault,repairing the defective valve is not only time and labor intensive, butin many cases entails extensive tear down of the engine itself. Insevere cases the condition of the engine may dictate complete enginereplacement.

In recognition of the foregoing problems attending presently known valveassemblies the present invention provides a unitary valve mechanismcomprising a module including a valve, valve seat, valve stem, returnspring, cam follower and housing with an inlet or outlet port which iscapable of being quickly installed and removed as a unit with minimumdisturbance of engine parts. A defective module may be replaced quicklywith a new module and discarded, returned to a central manufacturingsource for rebuilding or repaired locally as desired. In any event, theon site time and effort required to cure a defective valve problem inaccordance with this invention is reduced to a minimum.

It is an important object of this invention to provide a novelpre-assembled valve mechanism adapted to be operably installed andremoved as a modular unit.

It is another important object of this invention to provide a modularvalve assembly useful for intake or exhaust valve functions in internalcombustion engines, pumps and like applications.

Still another object of this invention is to provide a valve assembly inthe form of a readily replaceable module having particular use in valveregulated mechanisms such as internal combustion engines and pumps, byway of example.

A still further important object of this invention is to provide annovel valve mechanism which promotes improved economies of production,repair and installation.

Having described this invention the above and further objects, featuresand advantages thereof will be recognized by those familiar with the artfrom the following detailed description of a preferred embodimentthereof, illustrated in the accompanying drawings and representing thebest mode presently contemplated for enabling those skilled in the artto practice this invention.

IN THE DRAWINGS:

FIG. 1 is a partial elevational view with portions thereof in section ofa rotary engine embodying the improved valve assembly of this invention;

FIG. 2 is an enlarged cross section of a portion of the engineillustrated in FIG. 1 showing the valve mechanism of this invention inopen position and indicating its relationship to related parts of theengine;

FIG. 3 is a partial elevational view of the engine similar to FIG. 1with portions thereof in section, showing the valve mechanism of thisinvention in closed position;

FIG. 4 is an enlarged partial cross sectional view of the engineillustrated in FIG. 3 and showing the relationship of parts for thevalve mechanism of this invention in closed position;

FIG. 5 is an enlarged longitudinal cross sectional view of the valveassembly of this invention divorced from the engine of FIGS. 1 and 3;

FIG. 6 is a longitudinal cross sectional view of the valve body seen inFIG. 5;

FIG. 7 is a cross sectional view of the valve guide shown in FIG. 5;

FIG. 8 is a side elevational view of the return spring shown in crosssection in FIG. 5;

FIG. 9 is a side elevational view of the valve shown in section in FIG.5;

FIG. 10 is a cross sectional view of the valve cam follower takensubstantially along vantage line 10--10 of FIG. 11 and looking in thedirection of the arrows thereon;

FIG. 11 is a top plan view of the cam follower;

FIG. 12 is a right hand end elevational view of the valve cam followershown in FIG. 11;

FIG. 13 is a schematic view showing the relationship of valve andcylinder actuating cams of the engine illustrated in FIGS. 1 and 3;

FIG. 14 is an enlarged top plan view of the valve cam shown in FIG. 13;and

FIG. 15 is a cross sectional view taken substantially along vantage line15--15 of FIG. 14 and looking in the direction of the arrows thereon.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning now to the preferred embodiment of this invention, illustratedin the drawings, initial references is made to FIG. 1 wherein a partialshowing of a rotary cam plate type engine is indicated generally at 20comprising a plurality of cylinders 21 carried radially of a rotor 22for movement with the rotor and a central, generally cylindricalcombustion chamber member 23 that is supported on a main bearing 24concentrically surrounding a stationary main shaft 25. (See FIG. 2) Twoparallel, stationary cam plates (not shown) having recessed cam tracks27 (see FIG. 13) are disposed adjacent opposite axial ends of the rotor22 to engage cam followers 28, rotatably mounted on pintles 29 extendingcoaxially from opposite sides of a generally cylindrical saddle means30. The saddle is moveable over the exterior of cylinder 21 and isconnected to a related piston 31 by means of a wrist pin 32 whereby thepiston may be reciprocated in response to movement of the rotor andsaddle in accordance with the configuration of the cam tracks 27.

A rotary engine having the general features and characteristics ofengine 20 hereof is described more fully in my U.S. Pat. No. 4,653,438issued Mar. 31, 1987. It is to be understood, however, that theparticulars of engine 20 are not pertinent to the present inventionother than to provide a context in which the novel valve assembly 34hereof finds useful application. As seen in FIGS. 1-4, the embodiment ofvalve assembly 34 is employed as an exhaust valve in engine 20.

With reference now to FIGS. 1-4 of the drawings, the features of valveassembly 34 will be described more fully.

As seen in FIGS. 1 and 2, valve assembly 34 is mounted in a cylindricalbore 35 extending inwardly of one axial end of the combustion chambermember 23 and in opposing alignment with a stationary annular valve cam36 carried in one end section 37 of a two piece engine housing,(partially shown in FIGS. 1 and 3). It will be noted that bore 35 has areduced diameter portion 38 at its inner end forming an annular shoulderwhich is abutted by a mating annular stop shoulder 39 at theoperationally inner end of the valve assembly 34 for reasons to appearpresently. Bore 38 openly communicates with a combustion chamber 40within member 23 that in turn openly communicates with the inner radialend of a combustion cylinder 21 individually associated with chamber 40;there being several such chambers 40 in member 23 corresponding to thenumber of engine cylinders. Each combustion chamber 40 is invaded on oneside by a spark plug 41 and on its opposite side by a valve assembly 34.In this instance, the valve assembly serves to control the flow ofexhaust gases from the combustion chamber 40 via communicating ports42a, 42b and 42c and passageway 43 of shaft 25 leading to an exhaustoutlet 44 extending coaxially of such shaft.

As shown in FIG. 5 valve assembly 34 is generally cylindrical with it'svarious component parts coaxially arranged within a unitary cylindricalhousing 50. It will be recognized from sectional view FIG. 6 thathousing 50 has a cylindrical body 51 with exterior threads 52 adjacentone outer end 53 thereof. A cylindrical bore 54 extends axially inwardlyof end 53 and is provided with a pair of diametrically opposed slots 55,55 receptive of a spanner wrench for rotatably engaging threads 52 withthe internal threads formed in bore 35 of the combustion chamber member23 whereby to mount the assembly 34 in the engine 20 (FIGS. 1 and 4).

In this regard, engagement of shoulder 39 adjacent the inner end of body51, with the opposing shoulder formed by the reduced diameter portion 38in bore 35, serves to limit threading advance of body 51 into bore 35.This limit defined by stop shoulder 39 also assures proper alignment ofport 42a with port 42b of the exhaust ports and passageway as abovedescribed.

Bore 54 intersects a smaller diameter coaxial bore 56 extending inwardlyof the opposite or operationally inner end 57 of the assembly body 51;the junction between the two bores 54 and 56 forming an internal annularshoulder 58 in body 51, the purpose of which will be explained morefully hereinafter. Port opening 42a is formed through the side wall ofbore 56 for passage of exhaust gases through ports 42b in chamber member23 and 42c in the main bearing 24 to passageway 43 communicating withthe shaft exhaust outlet 44 as previously mentioned. The inner end 57 ofthe body 51 is distinguished by a frustro-conical annular valve seat 59which cooperates with valve 60.

As shown in FIG. 9, valve 60 comprises an elongated, ground cylindricalstem 61, having a reduced exteriorly threaded tail portion 62 at one endthereof, and an enlarged mushroom head 63 at its opposite end. The valvehead 63 is provided with a frustro-conical seat 64 which is matinglyengageable with the valve seat 59 at the outer end of the housing forthe purposes of periodically opening and closing the inner end 57 of thebody 51.

An annular valve guide 65 is shown in FIG. 7 to comprise a cylindricalsleeve body 66 having a reduced diameter portion 67 at one end to forman annular shoulder 68 about the body's exterior. The exterior diameterof body 66 fits closely within bore 54 of the housing 50 while theexterior diameter of portion 67 thereof fits closely within the smallerbore 56 of the housing body with annular shoulder 68 thereabout engagingshoulder 58 of the housing body 51. A cylindrical bore 69 extendscoaxially through body 66 and is dimensioned to closely receive thevalve stem 61 therethrough for guiding the valve during its movementscoaxially of the housing 50.

As shown in FIG. 8 a coil spring 70 surrounds the valve stem 61 with oneend 71 thereof abuttingly engaging an adjacently opposing end face 72 ofthe valve guide (see FIG. 5). The major portion of spring 70 fitsclosely within a cylindrical blind socket 73 extending axially inwardlyof an operationally inner end 74 of a valve cam follower member 80 (seeFIGS. 10-12). It will be noted that the other end 75 of spring 70bottoms against the end wall 76 of socket 73 and that a threaded bore 77extends coaxially beyond end wall 76.

Cam follower 80 has a generally cylindrical body 81 provided with aradially inset annular kerf 82 formed adjacent its inner end 74 and isfurther distinguished by an axially extending cam engageable tailportion 83 at its opposite end. Portion 83 is formed with a pair ofarcuate top and bottom faces 84 and 85, respectively, which arelaterally intersected by angularly convergent planar faces 86, 86 and atransversely related planar outer end face 87 (see FIGS. 11 and 12). Thetwo angular faces 86, 86 serve to engage risers 90 of the valve cam 36while the end face 87 of the follower periodically engages spaced lobes91 of the valve cam in operation (see FIGS. 13-15).

With particular reference now to FIG. 5, the organization of the severalparts of the unified assembly 34 will be apparent. As there shown, thecylindrical housing 50 is first fitted with the valve guide 65 byinserting the same coaxially into bore 54 until shoulder 68 engagesshoulder 58 at the junction of the two bores 54 and 56. Thisinterengagement of the shoulders provides a substantially gas-tight fit.

Once the guide 65 is in place, spring 70 is inserted into the blind borechamber 73 of the cam follower 80. It is to be noted that the kerf 82 ofthe cam follower is fitted with an O-ring seal 92, as shown in FIG. 5.The sub-assembly of the cam follower, spring and O-ring is then insertedinto bore 54 of the housing so that end 71 of spring 70 engages and wall72 of the guide sleeve 65. Next the valve 60 is inserted axially throughbore 56, the guide sleeve bore 69 and the open interior of spring 70until the threaded tail portion 62 thereof engages the threaded opening77 in the cam follower. The valve is then rotated to thread the tailportion 62 into the threaded bore 77, slightly compressing spring 70 anddrawing the cam follower 80 into its FIG. 5 position to completeassembly 34.

The unified assembly 34 is readily mounted in operating position in anengine such as engine 20 illustrated, for example, by inserting the sameinto combustion chamber bore 35 and engaging threads 52 on the exteriorof the assembly housing with the internal threads, adjacent the outerend of bore 35 (see FIGS. 2 and 4). The spanner wrench slots 55 areavailable to tighten the valve assembly into its operating positionwhere at the abuttment of stop shoulder 39 with the shoulder formed byreduced diameter 38 of bore 35 effects a substantially gas-tight seal,preventing hot exhaust gasses from reaching threads 52 which couldfreeze assembly 34 in bore 35. Rotational alignment of the valve,particularly the valve cam follower, is accomplished by two annularthrust bearings 93 and 94 mounted in housing 37 and disposed above andbelow the follower portion 83 to closely engage the arcuate surfaces 84and 85 thereon. In this latter respect, surface 84 is convex whilesurface 85 is concave; such surfaces being formed at different radii tofit the inner radius of the larger or upper ring bearing 93 and theouter radius of the smaller or inner ring bearing 94.

It will be appreciated from FIGS. 14-15 that movement of the valvefollower 80 past or off of a lobe 91 of the valve cam serves to expandspring 70 causing the valve 60 to move axially from its open position ofFIG. 2 to its closed position as shown in FIG. 4. Conversely, the valvereturns to its open position when the follower engages a riser 90 andraised cam lobe 91 (see FIGS. 2 and 13-15).

From the foregoing it is believed that those familiar with the art willreadily understand and appreciate the novel advancement of the presentinvention and will recognize that while the same has herein beendisclosed in relation to a particular described and illustratedpreferred embodiment thereof, the same is nevertheless susceptible tomodification, variation and substitution of equivalents withoutdeparting from the spirit and scope thereof which is intended to beunlimited by the foregoing except as may appear in the followingappended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A modular, pre-assembledvalve assembly designed to be installed and removed as a unitcomprising:a generally cylindrical housing having a lateral gas port andan adjacent valve seat constructed to be removably and insertablysecured completely within a mating socket formed in an external support,of an engine block; a valve having an elongated stem and a valve headcooperable with said valve seat; a stationary valve guide insertibleinto and supported on an interior wall portion within said housing tosupport said stem for coaxial movements therewithin; an axially moveablecam follower slidably disposed within said housing and engageable with avalve actuating cam located externally of said housing, and a springextending between an interior cylindrical blind socket within said camfollower for slidably receiving a major portion of said spring thereinand one end of said guide for biasing said valve head against said seatwhereby, said cylindrical housing is easily inserted into and removedfrom said engine block mating socket along with said valve guide, saidspring, said cam follower, said valve head, said valve seat and saidvalve stem as a single unit simultaneously.
 2. A modular, unitary valveassembly actuated by an external valve cam, comprising in combination:anelongated generally cylindrical housing having an axially extendingcylindrical interior with a frustro-conical valve seat at one endthereof; said housing having external threads at its other end foreffecting threaded assembling completely into and disassembling from amating socket formed in an external support of an engine block; anannular valve guide insertible into and supported on a wall portion ofsaid interior; a cam follower slidably mounted within said interior inaxially spaced relation with said valve guide comprising a tail portionextending outwardly of said the other end of said housing foroperatively engaging the external valve cam; a spring extending betweenand engaging one end of said guide and an interior cylindrical blindsocket within said cam follower for slidably receiving a major portionof said spring therein; and a valve comprising a head matinglyengageable with said valve seat and having an elongated stem extendingcoaxially through said valve guide and said spring and detachablyconnected with said cam follower whereby, said cylindrical housing iseasily inserted into and removed from said engine block mating socketalong with said valve guide, said spring, said cam follower, said valvehead, said valve seat and said valve stem as a single unitsimultaneously.
 3. The combination of claim 2, wherein said housing hasa lateral port communicating with said interior.
 4. The combination ofclaim 2, wherein said follower has an internally threaded socket and thevalve's stem has an externally threaded end portion connectable withsaid socket.
 5. The combination of claim 2 wherein said cylindricalinterior of said housing comprises a pair of axial bores of differentdiameters extending from opposite ends of said housing to form anannular shoulder at the intersection of said bores for engageablylocating said valve guide in said interior.
 6. The combination of claim5, wherein said valve guide comprises an annulus insertibly engageablewith said bores and having an external shoulder abuttable with saidannular shoulder to effect a substantially gas tight seal therebetween.7. The combination of claim 6, wherein said external threads serve todetachably connect the assembly to an internally threaded mating boreformed in said support.
 8. The combination of claim 7, wherein saidhousing has an external shoulder formed adjacent said one end forabutting a mating shoulder formed internally of said interior adjacentsaid valve seat whereby to effect a substantially gas tight sealtherebetween and limit threaded advance of said housing into said matingbore and align said lateral port with a cooperating passageway in saidsupport.